WINDOWS COMMUNICATION FOUNDATION

WINDOWS COMMUNICATION FOUNDATION: 

WINDOWS COMMUNICATION FOUNDATION www.otssolutions.com

Agenda: 

Agenda Introduction to WCF What is it? Why use it? Architecture Fundamentals and the ABCs of WCF Hosting Tooling Support Handling faults

Introduction to WCF: 

Introduction to WCF

What is WCF?: 

What is WCF? Stands for Windows Communication Foundation One of the 4 pillars of .NET 3.0 Microsoft’s unified programming model ( the service model ) for building Service-Oriented Applications

Different technology combined to form WCF.: 

Different technology combined to form WCF.

WCF Architecture: 

WCF Architecture

SOA: 

SOA Service Small program interacted by well defines message exchanges Agile, Reliable, Stable, Interoperable, Secure Four Tenets Boundaries are Explicit Services are Autonomous Services share schema and contract, not class Service compatibility is based upon policy

SOA solutions used : 

SOA solutions used

SOA Use for Mobile platforms: 

SOA Use for Mobile platforms

Windows Communication Foundation: 

Windows Communication Foundation WCF provides: an SDK for creating SOA a runtime for running Services on Windows Services send and receive messages All messages are SOAP messages WCF takes care of all the plumbing

Why use WCF?: 

Why use WCF? Interoperable and Standards based Supports WS-* protocols Unified Programming Model Unifies previous models like .NET Remoting , ASMX web services, COM+ etc Productive Programming Model Declarative Imperative Configuration based

WCF Value Proposition: 

WCF Value Proposition Simplicity Flexibility Maintainability Power

WCF: How does it work?: 

WCF: How does it work? Client Service SOAP Message SOAP Message SOAP over HTTP SOAP over Message Queues SOAP over TCP

WCF End points: 

WCF End points Client Service A B C A A B B C C A = Address (Where) B = Binding (How) C = Contract (What) A B C Message

WCF Endpoints : 

WCF Endpoints Every service has A ddress Where the service is B inding How to talk to the service C ontract What the service can do

Address: 

Address Combination of transport, server name, port & path Transport is determined by the binding Examples http://localhost:8001 net.tcp://localhost:8002/ MyService net.pipe :// localhost / MyPipe net.msmq :// localhost /private/ MyService net.msmq :// localhost / MyService http://server:345/Service

Bindings: 

Bindings Transport HTTP TCP MSMQ Message formats and encoding Plain text Binary Message Transmission Optimization Mechanism (MTOM) Communication security No security Transport security Message security Authenticating and authorizing callers

Out of the box Bindings: 

Out of the box Bindings BasicHttpBinding WSHttpBinding WS2007HttpBinding WSDualHttpBinding WSFederationHttp Binding WS2007FederationHttpBinding NetTcpBinding NetNamedPipeBinding NetMsmqBinding NetPeerTcpBinding WebHttpBinding MsmqIntegrationBinding

Contracts : 

Contracts Service contracts Defines operations, communications and behaviours . Data contracts Defines data entities and parameter types. Fault contracts Defines error types Message contracts Defines message formats

Service Contracts: 

Service Contracts [ServiceContract] – Defines a ‘set’ of operations [OperationContract] – Defines a single method [ServiceContract] public interface IService { [OperationContract] string GetData ( int value); } public class ConcreteService : IService { public string GetData ( int value) { ... } public string OtherMethod () { ... } }

Data Contracts: 

Data Contracts [ DataContract ] – Specifies type as a data contract [ DataMember ] – Members that are part of contract [ DataContract ] public class CustomType { [ DataMember ] public bool MyFlag { get; set; } [ DataMember ] public string MyString { get; set; } }

Alternative – DataContract: 

Alternative – DataContract DataContract : created specifically for WCF to serialize types Attribute contains Name and Namespace properties DataMember is needed to specify which properties/fields will form part of the contract Contains EmitDefaultValue , IsRequired , Name, Order properties

Metadata Exchange: 

Metadata Exchange Service can also expose endpoint for Metadata Exchange (MEX) It provides a mechanism for clients to find out about: Address of other end points Bindings that are used Contracts used – Service, Operation, Data, etc

Hosting: 

Hosting IIS HTTP only WAS (Windows Activation Service) Can use any transport Vista and Windows Server 2008 only Self hosting Can use any transport Can be hosted within Console, WinForms , etc Applications

Tooling Support: 

Tooling Support

Tooling Support: 

Tooling Support Visual Studio Separate projects for WCF “Add Service reference” menu WCF Configuration Editor WCF Service Host WCF Test Tool SvcUtil – To generate proxies SvcTraceViewer – To view logs

Handling Faults: 

Handling Faults

SOAP Faults: 

SOAP Faults Three main kinds of Exceptions can occur: Communication errors Unexpected error on the service Errors thrown by the service on purpose .NET Exceptions are technology specific All Exceptions come across the wire as SOAP Faults

Faults: 

Faults In WCF, SOAP faults are passed in as FaultException objects Rather than throwing Exceptions, services should throw FaultExceptions Or better still FaultException <T> Throwing FaultExceptions will not fault the proxy and the channel

FaultContracts: 

FaultContracts Specifies what kind of Exceptions, an operation can throw [ServiceContract ] public interface IEmployeeService { [OperationContract] [ FaultContract ( typeof ( ValidationException ))] public void AddEmployee (Employee e); }

Advantage: 

Advantage Its made of a lot of different components, so you can create new components for security, transport, authentication. In WCF, there is no need to make much change in code for implementing the security model and changing the binding. Small changes in the configuration will make your requirements. Its faster than ASMX Its Interoperability, for java, and more. WCF is interoperable with other services when compared to .Net Remoting , where the client and service have to be .Net WCF services provide better reliability and security in compared to ASMX web services.

Disadvantage: 

Disadvantage WCF is Microsoft's implementation of SOA and hence its APIs are solely controlled by MS which makes interoperability a bit difficult. To deploy WCF apps, need more underlying hardware resources on the platform on which the WCF applications will be running, since there is an additional layer of abstraction to deal with.

Summary: 

Summary WCF provides a runtime for creating Service Oriented Apps Provides a productive programming model. Takes care of: Messaging and Exchange formats All Plumbing: Transaction, Reliability, Security, etc Supports Declarative (via attributes), Imperative (via code) and Configuration based (via config files) programming model ABCs of Endpoints Address: Where to go? Binding: How to get there? Contract: What to do? Hosting IIS, WAS, Self-hosting

PowerPoint Presentation: 

Thank You http://www.otssolutions.com/

PowerPoint Presentation: 

http://www.otssolutions.com/ India Gurgaon ( Haryana ) 795, Udyog Vihar , Phase-V Gurgaon (Haryana) India Ph: +91 124 4101350 +91 124 4748100 Write to us at: sales@otssolutions.com United kingdom 88 Wood Street 10th Floor London EC2V 7RS Ph: +44 208 099 1660 Write to us at: sales@otssolutions.com USA 4433 Merlin Way , Soquel CA 95073 United States Ph: +1 408 540 0001 Write to us at: sales@otssolutions.com